Air separator



Dec. 2, 1924. LSVQO@ R. M. GAY

AIR SEPARATOR Filed March 9, 1923 2 Sheets-Sheet l R. M. GAY

A1B sEPARAToR Filed March 9, 1923 2 Sheets-Sheet 2 Patented Dee.. 2l,1924.

UNITED STATES PATENT orrlca.

BUBERT M GAY, OF HANOVER TOWNSHIP, MORRIS COUNTY, NEW JERSEY.

am sErAaA'roa Application led March 9, 1923. Serial No. 623,878.

To all whom it may concern Be it known that I, RUnER'r M, GAY, a citizenof t ie United States, residing in Hanover T wnship, State of NewJersey,

county have i of Morris, and nvented certain tion.

This invention relates to improvements in air separators solid materialto be wherein small particles of separated and gra-ded or classified arefed into a separating chamber and air is caused endless path and throughchamber, and wherein fines are separated from eoarser particles orseparating chamber,

to circulate through an the separating the fine particles or the heavieror tailings within the the fines being carried by the circulating air upthrough and out from `.the separating tailings settle within ,thechamber from the bottom thereof thr discharge opening.

chamber while the and pass ough a suitable The object of my invention isto provide a separator of novel, simple and efficient constructionhaving provision: the air passing through lirst, whereby the separatingchamber may be rotated in a manner to cause the rejection by centrifugalaction of the finer particles of the tend to follow the wardly throughand from chamber; second, whereby i tailings which fines as they passupthe separating the finer particles of the tailings thus rejected maybe collected and returned to the lower portion of the separating chamberin a manner to prevent them from being carried from the separatingchamber with the iines; third, whereby the speed of the air as it passesfrom the exterior to the interior of the separating chamber may begoverned and whereby the rotating air prevented and regulated, currentmay be from causing tailings to pass` out through the air passageleading from the exterior to the vinterior of chamber and to the theseparating tailings assa e F* 7 fourth, whereby the speed of the air inits travel through the separating chamber may be varied by 4adjustingthe means which causes the rotation of the air within the chamber andwithout changing the means which causes the air to circulate through ltsendless path; and, fifth, whereby various novel and advantageous resultsare procured.

With the foregoing and related objects in view, the invention consistsin the novel cona horizontal section through the separator, on line 2--2of Fig. 1.

Figure 3 is a horizontal, sectional detail, on line 3-3 of Fig. 1,showing part of the mechanism for adjusting the adjustable defleetingplates. l

Figure 4 is a vertical, sectional detail, on line 4--4 of Fig. 2,showing one of the fixed deiecting plates and the support therefor.

Referring to the drawings, 5' designates an outer casing comprising acylindrical uppertportion and a tapered or conical lower portion.`Within the outer casing are upper and lower inner casings 6 and 7supported in spaced relation to each other and to the outer casing 5 bysuitable brackets 8 S0 and 9, respectively, which extend from the iouter casing. The upper, inner casing 6 comprises an upper cylindricalportion and a lower tapered or conical portion. The lower, inner casing7 is conical in shape and 85 terminates at its lower end in a downwardlyand outwardly inclined pipe or passage 10 which extends through the wallof the outer casing 5 for the discharge of the .talings from themachine; and the lower end of the outer casing 5iterminates in adownwardly extending pipe or passage 11 for the discharge of the finesfrom the machine.

The upper, inner casing 6 encloses the separating or classifying chamber12, its open bottom providing van inlet for air and and outlet fortailings, and the central opening 13 in its top Wall 14, providinganoutlet for air and for the lines carried by the air.

The space surrounding the upper, inner casing 6 between it and wtheouter casin 5, the space between the top walls 14 an 15 of the inner andouter casings 6 and 5, re-

spectively, the space between the upper and lower inner casings 6 and7and the separating vchamber 12 form an endless passage through whichair may be circulated` in the direction of the arrows in Fig. 1.

he material to be separated or classi tied is fed to the chamber 12through a feed pipe 16 which extends centrally through the top wall 15of the outer casing 5 and through a. hollow Shaft 17 which also extendsthrough casing wall 15. The hollow shaft 17 is mount-v ed to turn inupper and lower bearings 18 and 19, respectively, carried by a hollowcasting 20 which is mounted on the top wall 15 of the casing 5. Thecasting 2() extends down into the casing 5 to support the lower`-bearing 19 some distance below the top wall '15 of the casing, and italso extends above the top wall 15 to support the upper bearing 18 somedistance above the top wall 15. This construction enables me tostabilize the lower free end portion of the sha-ft 17 and the partscarried thereby which are located a considerable distance below the topwall 15. The shaft 17 is supported by a collar 21 fixed thereon andresting upon a thrust bearing 22 carried by the casting 20; and the feedpipe 16 is supported above the top of the shaft 17 by the cap or cover23 which closes the top of the hollow casting 20.

The hollow casting 2O provides a chamber 24 for housing co-acting bevelgear wheels 25 and 26 for driving the shaft 17. The gear wheel 25 .isfixed on the shaft 17 and the gear wheel 26 is fixed on the inner end ofa horizontal shaft 27. The shaft 27 turns in a bearing 28 carried by thecasting 2O and a bearing 29 carried by one of two horibontal beams 30which support the entire separation by means of angle bars 31 secured tothe top of the outer casing 5 and resting upon the beams 30. The outerend portion of the shaft 27 is provided with a pulley 32 by means ofwhich power may be applied to the machine to drive the shaft 17.

The bottom of the shaft 17 carries two round, horizontally arrangeddiscs or plates 33 and 34 which are spaced one above the other, theupper plate 33 being secured to the flange of a collar 35 carried by theshaft 17, and the lower plate 34 being' carried by spaced boltsextending between the two plates. The upper plate 33 has a centralopening therein through which the lower end of the hollow shaft 17extends to discharge material from the pipe 16 upon the central portionof the lower or distributing plate 34 which, during the rotation of theshaft 17, discharges the' material from the edge thereof. by centrifugalaction and distributes it around the separating chamber 12 so that theparticles of the material will fall from the edge of the plate 34 in anannular stream or shower,

"Larnaca A. fan 36 is arranged to rotate within that portion of the airpassagewhich extends between the top Walls 14 and 15 of the outer andinner casings 5 and 6. The fan 36 com rises a hollow hub 37 secured tothe shafi? 17 below the bearing 19, arms 38 extending radially from theupper portion of the hub 37 and blades 39 carried by the outer endportions of the arms. The fan blades 39 are set to cause air within thecasing 5 to circulate throughthe endless air passage in the direction ofthe arrows in Fig. 1, during the rotation of the shaft 17. The upperportion of the hollow huh 37 surrounds the shaft bearing 19 in spacedrelation thereto and is adapted to contain oil for lubricating thebearing 19.

A fan 40 is arranged within the separating chamber 12 above the ,plates33 and 34. and it comprises a collar 41 secured to the shaft 17, arms 42extending radially from the collar 41 and blades 43 carried by the outerend portions of the arms 42. The fan 4() is provided to rotate thecirculating air current as it passes up through the separating chamber12. The arms 42 are adjustable about their axes to permit the blades 43to be set at different inclined positions to increase or decrease thespeed at which the air moves upwardly through the chainber 12, so thatthe blades may, in addition to providing a means to rotate the aircurrcnt.\vitl1in the separating chamber, also provide a means forregulating the speed of the air current circulated by the fan 36.

Within the separating chamber 12 some distance below the top or airoutlet opening 13 thereof and in close proximity to the fau 40 is ahorizontal disc-like plate 44 forn'iing a baiile for the ascending aircurrent` for a purpose hereinafter explained. The plate or baille 44 iscarried by the collar 41 and it surrounds the shaft 17 and extendsoutwardly therefrom and has its outer edge spaced from the surroundingcasing 6.

lVithin the lower portion of the upper, inner casing 6 is an annularpartition 45 having an upper cylindrical portion and, a lower tapered orconical portion following the lines of cylindrical and conical portionsof the casing 6. The partition 45 is supported within the casing 6 inspaced relation thereto to provide a central passage surrounded by itr`and to provide an annular passage between it and the casing 6 throughwhich the material being separated may fall. The distributing plate 34is located within the passage surrounded by the partition 45 so that theshower of the particles of inaterial from theiplate 34 will be.discharged within this passage.

The wall of the upper, inner casing 6 above the annular partition 45 isprovided with inwardly projecting bailies 46 which extend upwardly anddownwardly and rovide u wardly and downwardly exten ing channe s 47between them for the reception of articles of the material beingseparated, and) the guidance thereof to the annular passage between thewalls 6 and 45. These bafiles 46 may be formed in any suitable .inanner.As herein illustrated, they are formed of sheet metal suitably securedto the wall ofthe casing 6 and having vertically extending corrugationstherein which form the baliles and interposed channels 47.

Arranged to intercept the currentof air as it enters and passes throughthe space between the upper and lower casings and 7 .is an inner,circular series of spaced deflectin plates 48 and an outer, circularseries o spaced deflectingplates 49 which surrounds the inner series 48.The deecting plates 48 and 49 extend vertically between upper and lowerflanges or supporting rings 50 and 51 connected to or formed on thebottom of the upper casing 6 and the top of the lower casing 7 andextending outwardly therefrom. The plates 49 are secured to thesupporting rings 50 and 51 by bolts 52 which extend therethrough andthrou h lugs 53 formed on the plates 49. The p ates 48 are carried by a`circular series of shafts 54 extending vertically between and mounted toturn in bearings in the supporting rings 50 and 51. The detlectingplates of each series thereof 48 and 49 are arranged tangentially anddiverge from the plates of the other series in the same generaldirection around each series thereof, so that the air passing betweenthe upper and lower casings 6'and 7 will be obliged to traverse asinuous course, as shown by the arrows in Fi 2, for a purpose presentlyappearing.

he deiectin plates of the inner series 48 are adjusta le about the axesof the shafts 54 carrying them to change the angles thereof relativelyto the plates of the outer series 54, and also to widen or narrow theair passages between the plates 48. The shafts 54 extend below thebottom supporting ring 51 and they are provided on their lower ends withpinions 55 in mesh with a gear ring 56 which is mounted to turn onsuitable brackets 57 projecting from the lower casing 7, whereby, whenthe gear ring 56 is turned, the pinions 55 and their shafts 54 will beturned simultaneously to adjust the plates of the series 48, aspreviously described. As a suitable means to turn the gear ring fortheadjustment of the plates 48, I provide a vertical shaft 58 whichextends through the lower portion of the casing 5, and has a handle 59fixed on the lower end portion thereof exteriorly of the outer casing 5.The shaft 58 is mounted to turn in a bearing 60 on the casing 5, and theupper end portion of the shaft is `the separating chamber 12 'thedeiiecting plates `the upper end of the provided with a gear Wheel 61which is in mesh with the gear ring 56 and which is adapted to turn thesame of the plates 48 when the handle 59 is turned.

The operation of the machine isas follows:

Power is applied to the pulley 32 to rotate the shafts27 and 17 andtherewith the fans 36 and 43 and the distributing plate 34. The fan 36causes the air within the Outer casing 5 to circulate through theendless path indicatcd by the arrows in Fig. 1, and the fan 43 causesthe circulating air to be rotated as it passes through the separatingchamber 12 above the distributing plate 34 therein.

As the air is thus circulated it changes its velocity at a number ofplaces in its path of travel due to expanded and contracted portions ofthe passage through which it travels. Its velocity is increased as itpasses the bafi'e 44, which reduces the area of that portion of the airpassage which extendsbetween the edge of the baffle 44 and thesurrounding partition 45, and its velocity is decreased in the increasedarea of above the baftie 44 and beneath the top Wall 14 of the chamber12. Its velocity is again increased as it passes through the contractedoutlet opening 13 lof the separating chamber, and, thereafter, itsvelocity decreases and it ex'- pands as it passes down through theincreased area of the passage surrounding the upper inner casing 6 fromthe fan 36 to 49. The velocity of the ascending air current passingthrough the annular passage surrounding the partition 45 is less than itis in the contracted portion of the central passage between thepartition 45 and battle 44.

The material to be separated is fed into feed pipe 16 and it consists ofparticles of various sizes, which, for purposes of description, I shalldivide into three classes, i. e. the heavy particles, the intermediateparticles and the fine particles, it being desirable that the machineshall reject all particles;l over a predetermined size which constitutethe tailings and which include what I shall refer to herein as the heavyand intermediate particles.

These particles of material being fed into the feed pipe 16 descendtherein to the central portion of the distributing plate 34 and moveoutwardly thereon by centrifugal action, and are discharged from theedge thereof into the separating chamber 12 and into the ascending aircurrent therein. The heavy and some of the intermediate particles ofmaterial descend from the plate 34 within the surrounding partition wallfor the adjustment the machine by gravity through 45 and fall into thelower casing 7, while the fine particles and some of the lighterintermediate particles of the material are carried upwardly-.by theascending air current into the upper portion of the separating chamberand above the baille 44 where the air current is rotated by the fan 43and where the upwardly moving intermediate particles are rejected by thecentrifugal action of the rotating air causing them to move outwardly tothe outer portion of the chamber 12 and in close proximity to or incontact with the corrugated wall forming the batlles 46 where theascending velocity of the air current is somewhat less than it is nearerto the central shaft 17, and where the intermediate particles descend bygravity, while the finer particles are carried on upwardly and outthrough the opening' 13 by the upwardly moving air. The intermediatelparticles thus rejected by the rotating air current descend thrbugh theannular passage between the partition 45 and the wall of the casing 6and on down into the lower casing 7 with the tailings whichdescendthrough the passage surrounded by the wall 45.

rIthe fine particles or fines by the circulating air current out throughthe opening 13 and outwardly over the top wall 14 and into that portionof the air passage which surrounds the upper inner casing 6 and whichforms an expansion chamber for the air current, allowing it to slow downand permit the line particles of the material to descend by gravity toand through the lower or conical portion of the outer casing 5. Some ofthe tine particles will be carried by the air current toward the openingbetween the upper and lower inner casings 6 and 7, and upon meeting thebattle formed by the deiecting plates 48 and 49, most or all of thedesired tine particles will be thereby prevented from re-entering theseparating chamber 12 and be permitted to descend exteriorly of theinner casings 6 and 7.

rThe fine particles or fines pass from the outlet passage 11, and theheavy and intermediate particles 'or tailings pass from the machine bygravity through the outlet passage 10.

The baiiles 46 are encountered by the intermediate particles during therejection thereof as they are carried around the chamber 12 by therotating and ascending air current therein, and they are collectedwithin the channels 47 between the baffles 46 and descend therein to theannular passage surrounding the partition 45.

rllhe -centrally arranged, horizontal baille plate 44 above the fan 43prevents the intermediate particles from being carried into the upperportion of the separating cham- 'of the separating chamber are carried.

ber 12 too close to the shaft 17 and ensures the rejection thereof bythe rotating air current before they reach the outlet opening 13 Theholes or openings in the .fan blades 43 permit some of the air beingrotated thereby and some of the particles of material carried by the airto pass through the same, thereby distributing the e'ective area of thefan blades 43 over a wide range while presenting a relatively small areaof fan blade surface to strike against the ascending particles ofmaterial and beat or throw them violently outward.

'lhe sinuous course for the air current formed between the deflectingplates 48 and 49 changes the direction of movement of the air andthereby assists in preventing any oi' the fines which have passed fromthe separat`ng chamber 12 from re-entering the same through the spacebetween the upper and lower, inner casings 6 and 7; and the adjustable,inner deflecting plates 48 form a damper device which may be adjusted byturning the handle 59 to regulate the volume and velocity of the aircurrent passing through the space between the upper and lower, innercas'ngs 6 and 7. rlhe deflecting plates 48 also serve to prevent thecentrifugal action which discharges the material from the distributingplate 34 from throwing any of the tailings out through the openingbetween the upper and lower, inner casings 6 and 7, and ensures theirentrance into the lower casing 7 and their discharge from the machinethrough the passage 10.

l claim as my invention:

In an aix-,separator and in combination, a casing having a separatingchamber provided with andiir outlet opening in the upper portion thereofand an air inlet opening 1n the lower portion thereof, means to cause acurrent of air to pass upwardly throughsaid chamber, means to rotate theupwardly moving air, and means to supply particles of solid material tobe graded to said chamber, said casing having inwardly extending bafflesforming upwardly and downwardly extending channels between them for thereception and guidance of the larger particles of said material.

In an air separator and in combination, a casing having a separatingchamber provided with an air outlet opening in the up per portionthereof and an air inlet opening in the lower portion thereof, means tocause a current of air to pass upwardly through said chamber, means torotate the upwardly moving air, an annular partition within the chamberin spaced relation to and surrounded by said casing and separating thechamber into a central passage enclosed by the partition and an annularpassage surwardly extendin rounding the passage, and means to supplyparticles of solid material to be graded to said central passage, Saidcasing having inbafiles above said partition forming'upward y anddownwardly extending channels between them for the reception andguidance of the larger particles of said material to said annularpassage.

3. In an air separator and in combination, an outer casing, an uppercasing enclosing a separating chamber and supported within the outercaslng in spaced relation thereto and having an open bottom and an open.top, a lower casing supported within the outer casing the upper casingand having an open top, means to cause air to circulate through thespace between the up er and'lower casings, up through said cham er anddown through the outer casing exteriorly of said chamber, means torotate the upwardly moving air within the chamber, and means to supplyparticles of solid material to be graded to said chamber, said uppercasing having bafiies extending into sa.d chamber and forming upwardlyand downwardly extending channels between them for the reception andguidance of the larger particles of material.

4. In an air separator and in combination, a casing having a separatingchamber provided with an air outlet opening in the upper portion thereofand an air inlet opening in the lower portion thereof, a verticallyarranged, rotatable shaft extending centrally into the chamber, means tocause a current of air to pass upwardly through the chamber, a fancarried by the shaft for rotating the upwardly moving air, a horizontalbale surrounding the shaft and extending outwardly therefrom above thepath of the fan a substantial distance below said outlet opening andhaving its Outer edge portion spaced from the surrounding casing,causing the ascending air to pass between said casing and said edgeportion, and means `to supply particles of solid material to be gradedto the chamber below the baille.

5. In an air separator and in combination, a casing having a separatingchamber provided with an air outlet openmg in the` upper portion thereofand an air inlet opening in the lower portion thereof, a verticallyarranged, rotatable shaft extending centrally into the chamber, means tocause a current of air to pass upwardly through the chamber, a fancarried by the shaft for rotating the upwardly moving air, a horizontalbaiiie surrounding the shaft and extending outwardly therefrom above thepath of the fan and having its outer edge portion spaced.' from thesurrounding casing, an

means to supply particles ofsolid material to be graded to the chamberbelow the baffle, said casing having inwardl extending baffles above thehorizontal ba e and formbelow and 1n spaced relation to ing upwardly anddownwardly extendin channels between them for the reception an yguidanceof the larger particles of said material.

6. In an air separator and in combination, a casing having a separatingchamber provided with an air outlet opening in the upper portion thereofand an air inlet opening in the lower portion thereof, a verticallyarranged rotatable shaft extending central- Iy into the chamber, meansto cause a current of' air topass upwardly throu hl the chamber, a fancarried by the shaft or rotating the upwardly moving air, an annularpartition Within the chamber in spaced relation to and surrounded bysaid casing and separating the chamber into a central pas' sage enclosedby the partition and an annular passage surrounding the passage, ahorizontal baiiie surrounding the shaft and extending. outwardlytherefrom above the path of the fan and having its outer edge portionspaced lfrom the surrounding casing, and means to supply particles ofmaterial to be raded to said central passage below the ba e, said casinghaving inwardly extending bailles above said partition and above thehorizontal baffle and forming upwardly and downwardly extending channelsbetween them for the reception and guidance of the larger particles ofmaterial to said annular passage. 7. In an air separator and incombination, a casing having a separating chamber provided with an airoutlet opening in the upper portion thereof and an air inlet opening inthe lower portion thereof, a vertically arranged, rotatable shaftextending centrally into the chamber, means to cause a current of air topass upwardly through the chamber, a fan carried by the shaft forrotating the upwardly moving air, said fan having openings thereinthrough which portions of the air may pass during the operation of thefan to reduce the eRectiveness thereof, and means to supply particles ofsolid material to be graded to said chamber. 8. In an air separator andin combination, a casing having a separating chamber provided with anair outlet opening in the upper portion thereof and an air inlet openingin the lower portion thereof, a vertically arranged, rotatable shaftextending centrally into the chamber, means to cause a current of air topass upwardly through the chamber, a fan blade carried by said shaftwithin said chamber and adjustable on a radial axis to differentinclined positions to rotate the upwardly moving air and to vary thespeed 'thereof within said chamber as effected by said means, and meansto supply particles of solid material' to be graded to said chamber. 9.In an air separator and in combination,

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an outer casing, an upper casing enclosing a separating chamber andsupported within the outer casing in spaced relation thereto and havingan open bottom and an open top, a lower casing supported within theouter casing below and in spaced relation to the upper casing and havinan open top, a vertically arranged, rotata le shalt extending centrallyinto the chamber, a tan carried by the shaft within the outer casing andabove the upper casing to cause air to circulate through the spacebetween the upper and lower casings, up through the chamber and downthrough the outer casing exteriorly of the chamber, a fan blade carriedby the shaft within the chamber and adjustable on a radial axis todifferent 1nclined positions to rotate the upwardly moving air and tovary the speed thereof within said chamber as effected b f the firstnamed fan, and means to supply particles of solid material to be gradedto said chamber.

l0. In an air separator and in combination, an outer casing, -an uppercasing enclosing a. separating chamber and supported within the outercasing inspaced relation the-reto and having an open bottom and an opentop, a lower casing supported within the outer casing below and inspaced relation to the upper casing and having an open top, means tocause air to circulate through the space between the upper and lowercasings, up through said chamber and down through the outer casingexteriorly of said chamber, an inner, circular series of spaceddelecting plates extending vertically through the opening between theupper and lower casings, an outer circular series of spaced, verticallyextending, j delecting plates surrounding the inner series, the platesof each series diverging from the plates of the outer series in the samegeneral direction around each series, and means to supply particles ofsolid material to be graded to said chamber.

l1. lln an air separator and in combination, an outer casing, an uppercasing enclosing a separating chamber and supported within the outercasing in spaced relation thereto and having an open bottom and an opentop, a lower casing supported within the outer casing below and inspaced relation to the upper casing and having an open top, means tocause air to circulate through the space between the upper and lowercasings, up through said chamber and down through the outer casingexteriorly of said chamber, an inner, circular series of Yspaceddelecting plates extending vertically through the opening between theupper and lower casings, an outer circular series of spaced, verticallyextending, deflecting plates surrounding the inner series, the plates ofeach series diverging from the plates of the other series in the samegeniiimeoo eral direction around each series, the plates of one seriesbeing adjustable to change the angles thereof relatively to the platesof the other series, means opera-ble to simultaneously adjust theadjustable plates, and means lo supply particles of solid material to begraded to said chamber.

l2. ln an air separator and in combination, an outer casing, an uppercasing enclosing a separating chamber and supported within the outercasing in spaced relation thereto and having an open bottom and an opentop, a lower casing supported within' the outer casing below and inspaced relation to the upper casing and having an open to means to causeair to circulate-through the space between the upper and lower casings,up through said chamber and down through the outer casing exterior-ly ofsaid chamber, a circular series ol spaced, tangentially arrangeddelle'cting plates controlling the air passage between the upper-andlower casings, the plates of the series being adjustableI relatively toeach other to widen or narrow the air passages between them, meansoperable to simultaneously adjust the plates, and means'to supplyparticles of solid materials to be graded to said chamber.

13. ln an air separator and in combination, an outer casing, an uppercasing enclosing a separating chamber and supported within the outercasing in spaced relation thereto and having an open bottom and an ope-ntop, a lower casing supported within the outer casing below and inspaced relation to the upper casing and having an open top, vmeans tocause air to circulate through the space between the upper and lowercasings, up through said chamber and down through the outer casingextcriorly of said chamber, a circular series of spaced, tan entiallyarranged deflecting plates control in the air passage between the upperand lower casings, a circular series of vertically arranged shaftssupported by the upper and lower casings and carrying the deflectingplates, and means operable to simultaneously turn said shafts andthereby adjust the plates relatively to each other to widen or narrowthe air passage between them, and means to supply particles of solidmaterial to be graded to said chamber.

lst, ln an air separator and in combination, an outer casing, an uppercasing enclosing a separating chamber and supported within the outercasing in spaced relation thereto and having an open bottom and an opentop, a lower casing supported within the outer casing below and inspaced relation to the upper casing and having an open top, means tocause air to circulate through the space between the Lipper and lowercasings, up through said chamber and down through the outer casingexteriorly of said chamber, a circular series of spaced, tangentiallyarranged deeeting plates controlling the air passage between the upperand lower easings, a circular series of vertically arranged shaftssupported by the upper and lower casings and carrying the deflectingplates, pinions on said shafts, a gear ring rotatably supported by oneof .said casings and in mesh with said pinions, means operable to turnsaid ring and thereby simultaneously turn adjust the plates relativelyto each other to widen or narrow them, and means to supply particles ofsolid material to be graded to sald chamber.

In testimony whereof I affix my hereto. v

s HUBERT M. GAY.

said pinions and said shafts to l@ the air passages between.

signature 15

